The role of environment on the star formation history of disc galaxies

Xiaoyu Kang, Fenghui Zhang, Ruixiang Chang

Published 2017-04-25Version 1

NGC\,2403, NGC\,300 and M33 are three nearby pure-disc galaxies with similar stellar mass in different environments, they are benchmarks for understanding late-type spiral galaxies in different environments. The chemical evolution and growth of their discs are investigated by using the simple chemical evolution model, in which their discs are assumed to originate and grow through the accretion of the primordial gas, and the gas outflow process is also taken into account. Through comparative study of the best-fitting model predicted star formation histories for them, we hope to derive a picture of the local environment on the evolution and star formation histories of galaxies and whether or not the isolated galaxies follow similar evolution history. Our results show that these three galaxies accumulated more than 50 percent of their stellar mass at $z\,<\,1$. It can be also found that the metallicity gradients in isolated spiral galaxies NGC\,2403 and NGC\,300 are similar and obviously steeper than that in M33, when the metallicity gradients are expressed in ${\rm dex}\,R_{\rm 25}^{-1}$. The similar metallicity gradients in NGC\,2403 and NGC\,300 indicate that they may experience similar chemical evolutionary histories. The principal epoch of star formation on the discs of NGC\,2403 and NGC\,300 is earlier than that on the disc of M33, and the mean age of stellar populations along the discs of both NGC\,2403 and NGC\,300 is older than that of M33. Our results indicates that the evolution and star formation history of a galaxy indeed depends on its local environment, at least for galaxies with stellar mass of $10^{9.2}\,\rm M_{\odot}\sim10^{9.7}\,\rm M_{\odot}$.